I could definitely see it happening. iPhone growth is already slowing down, Android growth can't keep up this pace forever (although I expect it'll be maintaining its lead thanks to areas like Africa). Given there's only 3 players at this point, 20%+ isn't a stretch at all.
The word 'Pentaband' means '5 Bands', from the Greek word 'pente' meaning '5'. For a phone to be pentaband it has to support 5 bands. If the phone has AWS support, it doesn't automatically mean that it is pentaband. The reason Wind and Mobilicity users like pentaband phones is because the reverse is true. We're not the only ones who like pentaband phones though, so please stop referring to phones that work on Wind and Mobilicity as pentaband. It causes unnecessary cofusion.